TEMPERATURE-DEPENDENCE OF THE UPS AND HREELS OF HN3 AND DN3 ON SI(110)

HN3 was used for the first time as a nitrogen source for nitridation of Si surfaces. Its interaction with Si(110) was studied with HREELS and UPS at temperatures between 120 and 1350 K. HN3 was found to adsorb molecularly on the Si surface at 120 K, as all molecular vibrational peaks, such as HN-NN stretching at 150 meV, HNN = N stretching at 265 meV and H-NNN stretching at 414 meV, were clearly observed in HREEL spectra. A similar HREELS study of DN3 was carried out to confirm some of the EELS assignments. Upon warming up to 220 K, HN3 started to dissociate into N2 and NH, which further dissociated to give N and H as the surface was annealed from 580 to 800 K. H adatoms were observed to desorb at T > 800 K, while N remained on the surface, forming Si3N4 at T congruent-to 1350 K.